1. Field of the Invention
The present invention relates to an interchangeable lens.
2. Description of Related Art
Generally, at least one optical member whose driven state changes, such as a lens for focus adjustment or the like, is disposed within the interchangeable lens of a camera system in which the lens can be interchanged. The camera body needs information related to the driven state of this type of driven member (“driven information”) for various types of control. For example, in the camera system described in Japanese Laid-Open Patent Publication H10-68871, an encoder that monitors the movement of a lens transport system is provided. A drive amount monitor signal outputted by this encoder is fed back to a lens drive control CPU via lens side contact points that are provided to the lens mount unit and via body side contact points corresponding thereto that are provided to a mount unit upon the body. Moreover, with the camera system described in Japanese Laid-Open Patent Publication H10-68871, a main CPU within the camera body is coupled to a lens CPU or the like within the photographic lens via contact points other than those that transmit the monitor signal described above. The main CPU receives information needed for controlling the camera sequence and exposure operation from the other CPU or the like, and sends information about the required camera sequence to the other CPU. In other words, these contact points are contact points for general purpose communication performed between the main CPU and the lens CPU.